Women are the perfect weapon in a country where it is frowned upon culturally for a man even to approach a woman without her husband or father in tow, let alone frisk her for weapons at one of the many checkpoints that are the bombers’ favourite targets. In addition, it is easy to hide a vest packed with explosives under the traditional Islamic robes worn by women in Iraq without drawing suspicion.

In total, there have been 24 attacks involving women suicide bombers since January, including four on Monday in Baghdad and the northern city of Kirkuk that left scores dead. Al-Qaeda is “a very adaptive enemy”, a US Special Forces captain based in Diyala said. “They will try to use whatever works best for them to attempt to exploit whatever political or cultural restrictions we have.”

In the past, al-Qaeda fighters have used mosques to hold meetings and hide weapons, knowing that the US military will not raid religious buildings. “Now they’ve adapted to try to use female suicide bombers.”

The military believes that al-Qaeda employs a variety of tactics to get women to become suicide bombers. Some are easy prey because their husband or children have been killed or detained by US forces, said Captain Matthew Shown, the intelligence officer for “Sabre Squadron”, 2nd Squadron, 3rd Armoured Cavalry Regiment, which is based in southeast Diyala.

Another method is for a member of al-Qaeda to marry a woman and then dishonour her in some way, such as letting someone else rape her. “This would leave her with no choice but to end her life,” Captain Shown, 34, said.

There are also reports of women being told that their husband or child will be killed unless they agree to become suicide bombers.

Haynes also writes a blog from her vantage in Iraq, called Inside Iraq. Might have a butch at it. It’s not simply the bird’s bin between columns.